Single Left Ventricle Research Articles

Single Right Ventricles Have Impaired Systolic and Diastolic Function Compared to Those of Left Ventricular Morphology

Differences in single right ventricle (SRV) and single left ventricles (SLV) function are poorly described, although myocardial dysfunction is an important risk factor for morbidity and mortality. The aims of this study were to compare function between patients with SRVs and those with SLVs using newer echocardiographic techniques and to determine differences across staged palliation. In this cross-sectional study comparing 30 patients with SRVs and 30 with SLVs of similar ages (2.5 ± 1.7 vs 2.6 ± 1.6 years), patients were matched for surgical stage (20 pre-bidirectional cavopulmonary anastomosis, 20 pre-Fontan, and 20 post-Fontan patients). Circumferential and longitudinal strain, strain rate (SR), early diastolic SR, postsystolic strain index, and myocardial dyssynchrony index were measured. Comparisons between SRV and SLV parameters were made as a whole group and by subanalysis at each surgical stage. Patients with SRVs had reduced systolic SRs (circumferential: -1.0%/sec vs -1.2%/sec, P= .01; longitudinal: -1.1%/sec vs -1.3%/sec, P= .002), reduced early diastolic SRs (circumferential: 1.4%/sec vs 1.9%/sec, P= .03; longitudinal: 1.6%/sec vs 2.2%/sec, P= .001), and increased circumferential postsystolic strain indexes (8% vs 0%, P < .0001). Subanalysis at each surgical stage showed that the greatest disparity in systolic parameters occurred before bidirectional cavopulmonary anastomosis (longitudinal SR, P= .009; postsystolic strain index, P= .005) and that parity was regained after the Fontan procedure, while traditional diastolic parameters (E velocity, P= .004; E/E' ratio, P= .0003) were reduced in patients with SRVs after the Fontan procedure. The SRV has reduced contractility and diastolic function compared with the SLV. Ventricular systolic performance in patients with SRVs was poorest before bidirectional cavopulmonary anastomosis, while differences in diastolic function were more prominent after Fontan completion.

Comparison of Fontan Survivors with and without Pacemakers: A Report from the Pediatric Heart Network Fontan Cross-sectional Study

Although many Fontan patients undergo pacemaker placement, there are few studies characterizing this population. Our purpose was to compare clinical characteristics, functional status and measures of ventricular performance in Fontan patients with and without a pacemaker. The National Heart, Lung, and Blood Institute funded Pediatric Heart Network Fontan Cross-Sectional Study characterized 546 Fontan survivors. Clinical characteristics, medical history and study outcomes (Child Health Questionnaire [CHQ]), echocardiographic evaluation of ventricular function, and exercise testing) were compared between subjects with and without pacemakers. Of 71 subjects with pacemakers (13%), 43/71 (61%) were in a paced rhythm at the time of study enrollment (age 11.9 ± 3.4 years). Pacemaker subjects were older at study enrollment, more likely to have single left ventricles, and taking more medications. There were no differences in age at Fontan or Fontan type between the pacemaker and no pacemaker groups. There were no differences in exercise performance between groups. CHQ physical summary scores were lower in the pacemaker subjects (39.7 ± 14.3 vs. 46.1 ± 11.2, P =.001). Ventricular ejection fraction z-score was also lower (-1.4 ± 1.9 vs. -0.8 ± 2.0, P =.05) in pacemaker subjects. In our cohort of Fontan survivors, those with a pacemaker have poorer functional status and evidence of decreased ventricular systolic function compared to Fontan survivors without a pacemaker.

Peripheral circulatory failure induced by intraoperative blood loss in an adult patient with unoperated left single ventricle and secondary polycythemia undergoing colonectomy

Peripheral circulatory failure induced by intraoperative blood loss in an adult patient with unoperated left single ventricle and secondary polycythemia undergoing colonectomy

Evaluation of short axis systolic function of single left ventricles using velocity vector imaging

Objective To investigate the short axis systolic function of children with single-left ventricle(LV),and to appraise the clinical value of velocity vector imaging(VVI) on assessing it.Methods The study group consisted of 14 patients with single-LV.The control group consisited of 14 age-matched normal children.VVI was used to analyse the circumferential and radial strain and strain rate of regional single-LV at the level of papillary muscle.Results Compared with values in control group,single-LV circumferential strain values were significantly lower in anterior septum,posterior septum,anterior wall,lateral wall and inferior wall(all P ＜0.05).Single-LV circumferential strain rate values were significantly lower in anterior septum,posterior septum,anterior wall,lateral wall and posterior wall compared with controls(all P ＜0.05). In control group,circumferential strain and strain rate were higher in inferior septum and anterior septum compared with other segments( P ＜0.05).Single-LV radial strain values were significantly lower in all segments compared with values in control (P ＜ 0.05).In control group,radial strain and strain rate of papillary muscle level showed no significantly difference( P ＞0.05).Conclusions Circumferential and radial systolic ventricular function are impaired in children with single-LV.VVI can be used as a quantitative tool in evaluating the short axis systolic function of single-LV. Key words: Echocardiography; Single ventricle; Ventricular function,left; Velocity vector imaging

Holmes Heart-A Simple Antenatal Diagnosis of a Complex Cardiac Anomaly? Fetal Echocardiographic Findings and Review

Double inlet left ventricle as a rare cardiac malformation comprises a broad spectrum of anatomic variants making its correct antenatal diagnosis challenging. We report on echocardiographic findings of three fetuses found to have a less frequent morphologic subgroup of double inlet left ventricle, namely Holmes heart, characterized by a single (left) ventricle connected to both atrioventricular orifices and normally related arteries. We addressed the pre- and perinatal management as well as additional abnormalities and discussed our experiences together with what is known from current literature.

Abstract 17418: Vector Velocity Imaging: A Reliable Tool to Quantify Myocardial Function and Predict Clinical Outcomes in Single Ventricle Patients

Background: Ventricular function is one of the factors that correlate with survival to second stage surgical palliation in single ventricle (SV) patients. Standard 2D echocardiography (2DE) has limitations in evaluating right ventricular function. Myocardial function can be reliably determined using Vector Velocity Imaging (VVI), which is an angle independent method of evaluating myocardial mechanics using conventional 2DE images. HYPOTHESIS: VVI provides a valid and reproducible measure of ventricular function in SV patients compared to standard 2DE with direct correlation to clinical outcomes. Methods: Medical records and 2DE's were retrospectively reviewed on 72 patients with SV's (37 systemic right ventricles, 35 systemic left ventricles. VVI analysis was performed offline using Siemens Syngo software. When feasible, 2D and Doppler parameters of ventricular function were performed. Using VVI on a 4 chamber image longitudinal velocity (LVel), strain (S), strain rate (SR) were obtained. Ventricular function was measured pre and post stage 1 palliation and compared to normals. Results: Fifty seven patients survived to stage 2 palliation (79%). Of the 15 deceased, 10 survived to hospital discharge; 10 had a single RV and 5 had single LV. Heterotaxy, post operative ECMO, sepsis, atrioventricular valve insufficiency and chylothorax were factors associated with death. Using 2DE, ventricular function was qualitatively normal in all but 3 patients pre-stage 1 and in 9 patients post stage 1. Other quantitative parameters were not consistently employed through the study period. LVel, S, and SR were depressed compared to normal hearts in all study patients. There was a statistical difference in the LVel between the survivors and non-survivors (p 0.017). Conclusions: Despite qualitatively normal ventricular function, VVI shows significantly decreased myocardial function in both single left and right ventricles when compared to normal hearts. In the absence of traditional quantitative measures of SV function, VVI is a reliable tool to evaluate myocardial mechanics and serves as an adjunct to prognosticate clinical outcomes.

ORAL PRESENTATION

ORAL PRESENTATION

Evaluation of Ventricular Filling Pressures and Ventricular Function by Doppler Echocardiography in Patients with Functional Single Ventricle: Correlation with Simultaneous Cardiac Catheterization

Elevated ventricular filling pressure is a marker of diastolic dysfunction and a known risk factor for failure of single-ventricle surgical palliation. Doppler echocardiography has been shown valuable in identifying patients with elevated ventricular end-diastolic pressure (VEDP) in other settings, but its utility in evaluating pediatric patients with single ventricle is unclear. The aim of this study was to compare Doppler parameters to simultaneous catheter measurements of VEDP in children with single ventricle. All consecutive patients (age < 18 years) with single ventricle who underwent simultaneous echocardiography and catheterization in 2009 and 2010 were included in this prospective study. Data regarding diagnosis, morphology of the "single" ventricle, prior surgeries, Doppler tissue imaging (DTI), atrioventricular valve inflow and pulmonary vein Doppler, and myocardial performance index (MPI) were collected. Ventricular Doppler echocardiography was performed from the dominant ventricle. Simultaneous Doppler and catheter measurements of systolic and diastolic function and VEDP were obtained. Correlation of continuous variables was examined using linear regression analysis. Receiver operating characteristic curves, two-sample Student's t tests, χ(2) analyses, and Fisher's exact tests were used as appropriate. A total of 32 patients (15 male; mean age, 30.2 ± 22 months) were studied (nine post-Fontan, 15 post-Glenn, and eight pre-Glenn). Mean systemic arterial saturation was 81 ± 10%, mean VEDP was 11 ± 3 mm Hg, and mean echocardiographically estimated ejection fraction was 55 ± 7%. VEDP was correlated positively with E/E' ratio (r= 0.44, P < .01), pulmonary vein atrial reversal duration (r= 0.77, P < .001), and E' (r= 0.49, P < .01). Receiver operating characteristic curve analysis using an E/E' cutoff of 12 showed sensitivity of 90% (95% confidence interval, 54.1%-99.5%) and specificity of 75.0% (95% confidence interval, 47.4%-91.7%) for identifying VEDP > 10 mm Hg. Single left ventricles had higher DTI S' and E' velocities and lower E/E' ratios and MPIs compared with single right ventricles. S' velocity correlated positively with ejection fraction (r= 0.77, P < .001) and negatively with single left ventricular MPI (r= -0.46, P < .01). In patients with single-ventricle physiology, DTI and pulmonary vein Doppler echocardiographic parameters correlated modestly with direct measurement of VEDP and may be helpful in identifying patients with elevated filling pressures. In addition, single left ventricles had better systolic and diastolic performance than single right ventricles. DTI systolic velocities and left ventricular MPI correlated well with ventricular ejection fraction.

Long-Term Functional Analysis of the Atrioventricular Valve in Patients Undergoing Single Ventricle Palliation

Presently, there are wide variations in cardiac anatomies requiring single ventricular palliation and these variations may have an impact on the incidence of atrioventricular valve regurgitation. In all, 363 patients underwent single ventricular palliation (1978 to 2008). Hearts were first classified into single right ventricle (156), single left ventricle (140), and two ventricles (63); and secondly into single mitral (90), single tricuspid (64), two separate valves (110), and common atrioventricular valves (95). The incidence of atrioventricular valve regurgitation and the necessity of repair were the highest with common atrioventricular valves, followed by tricuspid and mitral valves (p < 0.0001). The success rate (postoperative regurgitation of mild or less) of repair was similar (p = 0.9800). Estimated survival for patients having moderate or greater atrioventricular valve regurgitation was similar to the rest of the patients (p = 0.8705). Patients were more likely to have progressive mitral regurgitation in the presence of both mitral and tricuspid valves, compared with single mitral valve (p = 0.0207). There were 2 patients who had severe mitral regurgitation; both had a nonsystemic left ventricle isolated from the circulation by malposition of the great arteries and restrictive/remote ventricular septal defect. In contrast, coexisting mitral valves reduced the incidence of potential tricuspid regurgitation (p = 0.0012). If performed properly, atrioventricular valve repair may neutralize the risk of regurgitation regardless of the valve morphology. The effort to incorporate the mitral valve into the systemic circulation may be important to reduce tricuspid regurgitation. The effort to decompress a nonsystemic left ventricle, if present, may be important to avoid unfavorable ventricular interactions on the mitral valve.

Echocardiographic Assessment of Atrial Properties in Single Ventricles vs. Normal Controls

Atrial function is increasingly being recognized as a significant factor in overall cardiac function in adults. Limited studies evaluating atrial properties exist in the pediatric congenital heart disease population. The goal of this study was to evaluate atrial properties in patients with single ventricle physiology after Fontan completion and compare these values with normal control patients. Echocardiograms were performed in patients with single ventricular physiology and in control patients. Tissue Doppler and blood flow measurements were obtained. Atrial fraction and atrial electromechanical values were calculated. Differences were assessed with one-way analysis of variance. Post hoc comparisons were performed with Tukey adjustment. P < .05 was considered significant. No significant difference was present in age or heart rate between single ventricle and control patients. The single right ventricle tricuspid valve A wave (52.6 ± 14.5 vs. 36.7 ± 10.4 cm/s) and atrial fraction (39.2 ± 6.2 vs. 32.7 ± 7.7%) were significantly higher, and the E/A ratio (1.4 + 0.3 vs. 1.8 + 0.4), tricuspid valve E/A velocity-time integral (1.6 + 0.4 vs. 2.2 + 0.7 cm), and late diastolic annular value (5.3 + 1.5 vs. 8.7 + 1.4 cm/s) were significantly lower compared with the controls. The single left ventricle late diastolic annular velocity (4.2 + 1.0 vs. 6.7 + 1.3 cm/s) was significantly lower and atrial fraction was significantly higher compared with the controls (37.7 ± 12.5 vs. 29.8 ± 4.3%). There were no significant differences in atrial electromechanical measurements between groups, but the single right ventricle patients tended to have increased atrial dyssynchrony compared with controls. Patients with single ventricle physiology after Fontan completion have differences in atrial properties when compared with normal controls. These differences may have important implications in their long-term outcomes. Further studies are necessary to determine the clinical significance of these findings.

Diagnostic value of echocardiography in univentricle

Objective To explore the value of transthoracic echocardiography in diagnosis of univentricle and analyze the sonogram typing. Methods The results of 66 patients with univentricle were reviewed retrospectively,and analayzed their typing connected with the reports in the literature. Results There were 3 ultrasonic types in 66 cases:①Type A(single left ventricle) 19 cases,single ventricle with left ventricular shape,residual cavity in front of it. ②Type B(single right ventricle) 38 cases, single ventricle with right ventricular form,and residual cavity in the rear.③Type C (solitary single-ventricle) 9 cases,there was only one ventricle. Thirty-one of them were treated surgically, 5 cases without operation had MRI or cardiac catheterization examination and the remaining 26 patients were only observed by echocardiography,the positive rate of diagnosis in type was 100%, the results were compared with cardiac catheterization or MRI examination and the operation: 1 cases of mixed type total anomalous pulmonary venous connection was misdiagnosed as heart-type total anomalous pulmonary venous drainage. But 1 case of descending aorta limitations narrow complicated patent ductus arteriosus(PDA), PDA was missed. The rest were completely correct diagnosis. Conclusions The transthoracic echocardiography can be used to evaluate types and all containing malformations of univentricle,and offers reliable information for operation. Key words: Echocardiograghy; Heart defects,congenital; Single ventricle

Two-dimensional Speckle Strain and Dyssynchrony in Single Left Ventricles Vs. Normal Left Ventricles

Patients with single left ventricle (LV) physiology maybe at increased risk for myocardial dysfunction and mechanical dyssynchrony. Newer echocardiographic modalities may be able to better quantitate LV function in this unique population. Our objective was to use 2D-speckle analysis of strain and strain rate to quantify systolic function and dyssynchrony in single LV post-Fontan patients and compare them to control LV patients. Patients with single LV status post-Fontan procedure and patients with normal biventricular anatomy were studied. Two-dimensional speckle echocardiography was used to measure strain, strain rate, time to peak, and longitudinal displacement in a six-segment model of the LV. Independent t-tests were used to compare group means. Twelve patients with single LV physiology and thirteen control patients were studied. There was no significant difference in ages for the single LV patients vs. control patients (7.1 + 2.8 years vs. 5.7 + 1.8 years). Single LV strain values were significantly lower in four of the six segments compared with control LV (mid interventricular septal [IVS]: -19.3 + 6.4% vs. -23.8 + 3.5%, apical IVS: -20.8 + 5.4% vs. -27.4 + 4.7%, basal LV: -20.6 + 6.6% vs. -25.8 + 3.4%, and apical LV: -21.0 + 6.2% vs. -26.1 + 4.3%). Longitudinal displacement was lower for all three segments of the IVS for the single LV vs. control LV. Modified Yu index for strain and strain rate time to peak was longer in the single LV patients vs. controls (51.2 + 18.2 ms vs. 27.9 + 8.0 ms and 90.2 + 24.2 ms vs. 52.5 + 23.7 ms, respectively). Significant differences in strain analysis between single LV patients vs. control patients with normal biventricular physiology exist at a relatively young age. Future studies are needed to determine the significance of these differences.

Fenestration during Fontan palliation: Now the exception instead of the rule

Fenestration during Fontan palliation has traditionally been used to decrease surgical morbidity and mortality, particularly in high-risk cases. Potential limitations include oxygen desaturation, risk of paradoxic embolism, and need for late intervention. Our practice has evolved away from routine fenestration with increased extracardiac conduit use. We reviewed our experience with Fontan palliation and retrospectively assessed outcomes with decreased fenestration. Between January 2002 and April 2008, 226 patients underwent primary Fontan palliation. Outcomes were assessed by hospital stay, chest drain duration, short- and long-term survivals, and late interventions. Anatomic subtypes were single left ventricle (n = 88, 38.9%), single right ventricle (n = 78, 34.5%), common ventricle (n = 19, 8.4%), and heterotaxy syndrome (n = 41, 18.1%). Lateral tunnel connection was created in 69 patients (30.5%); extracardiac connection was created in 157 (69.5%). Mean age and weight at surgery were 4.3 +/- 3.8 years and 17.2 +/- 9 kg, respectively. In 2002, 14 of 16 patients (87.5%) had fenestrated Fontan circulations, versus 2 of 32 (6.3%) in 2008. Mean hospital stay was 10.8 +/- 8.8 days. Survival to discharge or 30 days was 98.7%. There were 2 (0.9%) late deaths during mean follow-up of 2.0 +/- 1.7 years. Outcomes were equivalent between fenestrated and nonfenestrated procedures across anatomic subtypes. Highly selective use of Fontan fenestration is achievable while maintaining excellent outcomes without increased surgical morbidity or mortality, irrespective of anatomic subtype. Risks of hypoxia, systemic embolism, and late instrumentation can be avoided in most cases.

Differences in Tissue Doppler Imaging Between Single Ventricles After the Fontan Operation and Normal Controls

Tissue Doppler imaging measurements could be used to quantitate ventricular function in patients with systemic single ventricles. The objective of the present study was to measure the tissue doppler imaging-derived indexes of function and dyssynchrony in patients with single ventricular physiology and compare these values with those from control patients. Echocardiograms were performed in patients with single left or right ventricular physiology and control patients. Measurements were made of the free walls at the level of the atrioventricular annulus. Differences were assessed with one-way analysis of variance. Post hoc comparisons were performed with a Tukey adjustment. No significant difference was present in age among the control (5.75 +/- 1.73 years, n = 16), single left ventricle (7.07 +/- 2.81 years, n = 12), or single right ventricle (6.25 +/- 2.2 years, n = 14) groups. The single right ventricular free wall peak systolic annular, peak early diastolic annular, and peak late diastolic annular velocities were significantly lower and the myocardial performance index and interval to mechanical activation greater compared to the controls. The single left ventricular free wall peak systolic annular, peak early diastolic annular, and peak late diastolic annular velocities were also significantly lower and the myocardial performance index and interval to mechanical activation greater compared to controls. In conclusion, significant decreases in systolic and diastolic function, as well as differences in dyssynchrony, using tissue Doppler imaging exist in patients with single ventricular physiology compared to control patients.

Associação de bronquite plástica com enteropatia perdedora de proteínas após operação de Fontan

We report an unusual case of association of plastic bronchitis (PB) to protein-losing enteropathy (PLE) in a girl of 4 years and 9 months of age with double inlet single left ventricle and ventriculoarterial concordance. submitted to total cavopulmonary surgery. with an intracardiac lateral tunnel at the age of three. The elimination of the 10 cm fibrin bronchial mold (PB) and the alpha-1-antitrypsin elevation of 52 mg/g in feces had both become outstanding. Using sildenafil. the thoracic duct ligature and the cardiac transplant were programmed in case of continuity of the process.

Discontinuous Pulmonary Arteries Do Not Preclude Good Fontan Outcomes

Discontinuous pulmonary arteries are believed to portend poor outcomes for a single ventricle palliation leading to Fontan's operation. This is a single institutional review of patients with single ventricle and discontinuous pulmonary arteries who underwent pulmonary artery centralization as part of staged surgical palliation. The study is a retrospective case series. From November 1997 to December 2005, 12 centralization procedures were performed on 12 single ventricle patients with discontinuous pulmonary arteries. The diagnoses at surgery were as follows: heterotaxy 67%, pulmonary atresia 75%, a single morphologic right ventricle 58%, a single morphologic left ventricle 33%, and functional single ventricle with atrial situs inversus 8%. The outcome was assessed by hospital survival, actuarial survival, and New York Heart Association (NYHA) classification at follow-up. The overall actuarial survival following centralization is 100% (95% confidence interval = 0.698 to 1). Seventy-five percent of the patients have undergone a Fontan procedure. Median McGoon ratio pre-Fontan = 1.65 (range: 1-2.1). Median follow-up after Fontan = 4.4 years (range: 1.2-9 years). Overall actuarial survival following Fontan is 100% (95% confidence interval = 0.428-0.911). Following the Fontan, there have been no thromboembolic complications, protein-losing enteropathy, nor Fontan takedowns. One hundred percent of the Fontan patients are NYHA class I. This experience indicates that a resuscitative strategy for discontinuous pulmonary arteries can result in good outcomes after the Fontan procedure. The presence of discontinuous pulmonary arteries in patients with single ventricle physiology should not preclude a management strategy with the goal of Fontan candidacy.

Biventricular noncompaction in a patient with dextrocardia/dextroversion diagnosed with cardiac magnetic resonance imaging

A five-year-old boy was referred for follow-up of a surgical correction of partial anomalous pulmonary venous return. Echocardiography and magnetic resonance imaging (cMRI) showed visceral heterotaxy with bilateral left atrial appendage morphology. The ventriculoarterial connection was concordant with dextrocardia/dextroversion. Multiple muscular ventricular septal defects near the apex were also observed. There were no ventricular outflow tract or aortic arch obstructions. A slightly increased flow was observed in the repaired pulmonary veins but there was no evidence of obstruction. The patient’s left ventricle (LV) demonstrated extensive trabeculations with flow into the deep intertrabecular recesses, which suggested the presence of LV noncompaction (Figure 1). cMRI confirmed the diagnosis of myocardial noncompaction in the LV (Figure 2). Most of the LV was affected, except for the basal part of the septum, with a noncompacted to compacted layer ratio of 4:1. The involved area showed significant thinning of the compact layer of the myocardium. Furthermore, there was involvement in the apical part and inferior wall of the right ventricle (RV) (Figure 2). Figure 1) Colour Doppler echocardiogram in parasternal short-axis view, showing penetration of colour into the deep intertrabecular recesses Figure 2) Short-axis fast cine magnetic resonance image of the ventricles shows typical lacy pattern of noncompacted left ventricular (LV) myocardium (arrows). Note that the LV free wall is more extensively involved than the ventricular septum. The compact layer ... Despite these findings, systolic function was within normal limits and the patient was asymptomatic. The patient continues to follow up on a regular basis. He remains off medications and has a normal level of activity with no symptoms or signs of heart failure, arrhythmia or thromboembolic events. Noncompaction of the ventricles is a newly recognized cardiomyopathy (1) that is believed to arise from arrested endomyocardial development during embryogenesis. The incidence of this cardiomyopathy in all pediatric patients receiving echocardiograms is 0.05%, but was found to be 2% in those patients with congenital heart disease (up to 22% in patients with single left ventricle) (2). Noncompaction has primarily been described in the LV; however, there have been reports of biventricular or isolated RV involvement (3). Because of increased trabeculations normally found in the RV, RV noncompaction is more difficult to diagnose than LV noncompaction. Ventricular noncompaction has been most extensively studied using two-dimensional and colour Doppler echocardiography. cMRI is increasingly being used to more accurately diagnose LV noncompaction. Borreguero et al (4) suggested the potential role of cMRI in the evaluation of the RV with noncompacted myocardium. Our patient represents an example of biventricular noncompaction in which cMRI aided the diagnosis. To our knowledge, the present patient is the first to be described with biventricular noncompaction in the presence of dextrocardia/dextroversion since the official description of this cardiomyopathy. A case with a similar biventricular “bizarre trabecular pattern” was published almost 30 years previously (5). However, in that case, there was no clear description regarding the extension and the ratio between the compacted and noncompacted myocardium. Furthermore, that case was associated with anomalies that generate significant intraventricular pressure overload.

Remote ischaemic pre‐conditioning does not attenuate ischaemic left ventricular dysfunction in humans

Remote ischaemic pre-conditioning (RIPC) reduces distant tissue ischaemia reperfusion injury. We tested the hypothesis that RIPC would protect the left ventricle (LV) from ischaemic dysfunction and stunning. Forty-two patients with single vessel coronary disease and normal LV function were prospectively recruited. Twenty patients had repeated conductance catheter assessment of LV function during serial coronary occlusions with/without RIPC and a further 22 patients underwent serial dobutamine stress echocardiography and tissue Doppler analysis with/without RIPC. Remote ischaemic pre-conditioning was induced by three 5 min inflations of a blood pressure cuff around the upper arm. RIPC did not diminish the degree of ischaemic LV dysfunction during coronary balloon occlusion (Tau, ms: 59.2 (2.8) vs. 62.8 (2.8), P = 0.15) and there was evidence of cumulative LV dysfunction despite RIPC [ejection fraction (EF), %: 54.3 (5.8) vs. 44.9 (3.7), P = 0.03]. Remote ischaemic pre-conditioning did not improve contractile recovery during reperfusion (EF, %: 51.7 (3.6) vs. 51.5 (5.7), P = 0.88 and Tau, ms: 55.6 (2.8) vs. 56.0 (2.0), P = 0.85). A neutral effect of RIPC on LV function was confirmed by tissue Doppler analysis of ischaemic segments at peak dobutamine (V(s), cm s(-1) control: 8.2 (0.4) vs. RIPC 8.1 (0.4), P = 0.43) and in recovery. RIPC does not attenuate ischaemic LV dysfunction in humans.

Extracardiac lesions and chromosomal abnormalities associated with major fetal heart defects: comparison of intrauterine, postnatal and postmortem diagnoses

The clinical outcome of prenatally diagnosed congenital heart defects (CHD) continues to be affected significantly by associated extracardiac and chromosomal abnormalities. We sought to: determine the frequency and type of major extracardiac abnormalities (with impact on quality of life) and chromosomal abnormalities associated with fetal CHD; and compare the extracardiac abnormalities detected prenatally to the postnatal and autopsy findings in affected fetuses, to find the incidence of extracardiac abnormalities missed on prenatal ultrasound. We reviewed the computerized database of the Division of Cardiology of the Hospital for Sick Children in Toronto to identify all cases of major CHD detected prenatally from 1990 to 2002. Medical records, fetal echocardiograms and ultrasound, cytogenetic and autopsy reports were reviewed. The types of CHD detected were grouped into categories and the frequencies of major extracardiac and chromosomal abnormalities in these categories were noted. Prenatal ultrasound findings were compared with those at autopsy or postnatal examination. Of 491 fetuses with major structural CHD, complete data were obtained for 382. Of these, there were 141 (36.9%) with major extracardiac abnormalities at autopsy or postnatal exam, of which 46 had chromosomal abnormalities and 95 did not. In the absence of chromosomal abnormalities, the organ systems most affected were urogenital (12.2%) and gastrointestinal (11.6%). CHDs with the highest incidence of extracardiac abnormalities (>25%) included: heterotaxy, single left ventricle and tricuspid atresia, hypoplastic left heart syndrome and tetralogy of Fallot. Ninety-four of 334 (28.1%) fetuses tested had chromosomal abnormalities. The most common chromosomal abnormalities were trisomies 21 (43.6%), 18 (19.1%) and 13 (9.6%), monosomy X (7.4%) and 22q11.2 deletion (7.4%). Of 289 extracardiac abnormalities from the complete series, 134 (46.4%) were not identified prenatally. Of the missed extracardiac abnormalities, 65 were considered not detectable at prenatal ultrasound, so 23.9% (69/289) of detectable extracardiac abnormalities were missed prenatally. Major extracardiac and chromosomal abnormalities are common in fetuses with major fetal CHD. Many important associated extracardiac abnormalities may be missed prenatally, which should be taken into consideration in the prenatal counseling for fetal CHD.

Outcome of Fetuses and Infants With Double Inlet Single Left Ventricle

Outcome of Fetuses and Infants With Double Inlet Single Left Ventricle